Corobate
Open Receipt Verifier · runs entirely in your browser

Verify an attestation receipt

Paste a receipt (a sample is loaded) and press Verify. Nothing is uploaded — the content hash and chain are recomputed here, in your browser, against draft-smith-corobate-attestation-receipt-00. This is the "re-run it yourself, trusting no one" step. Try the Tamper button: change one character and watch it break.

Full RFC 3161 token validation (the independent time anchor) is a signature check over the token; verify it with: openssl ts -verify -data head.bin -in head.tsr -CAfile ca.crt. The hosted verifier at verify.corobate.com performs this server-side. This page confirms content reproduction, the hash chain, the confidence gate, the point-in-time horizon, and that the anchor covers the head.
Patent pending — U.S. Patent Application No. 19/747,068.